不同磷效率大豆农艺性状与磷/铁利用率对磷素的响应

土壤中磷含量与植物铁的吸收密切相关,为研究供铁充足条件下不同P∶Fe配比对不同磷效率基因型大豆农艺性状和磷/铁利用率的影响,本文以前期筛选到的磷高效和磷低效大豆品种为试验材料,采用沙培方式和裂区设计研究不同P∶Fe比对大豆生物学性状的影响及基因型差异,并利用因子得分综合评价磷高效和磷低效基因型对不同P∶Fe处理的响应,以解析农艺性状与大豆体内磷/铁利用率的关系,从而为磷、铁肥合理施用提供理论依据。结果表明:(1)R5期,磷高效基因型在各处理下的株高、茎粗、根干重和地上部干重增长相对较快,且均大于磷低效基因型;磷高效和磷低效基因型在P∶Fe比为100∶100处理下的R5期单株根干重较低,而百粒重较大。此外,磷高效和磷低效基因型的籽粒磷利用率在P∶Fe比为1000∶100时降至最低。(2)典型相关分析表明,磷高效基因型R5期的茎粗与叶片铁利用率呈正相关关系,而磷低效基因型R5期的地上部干重与叶片磷利用率呈负相关关系。(3)R8期单株地上部干重和R3期叶片磷利用率的增加有助于磷高效基因型单株粒重的增加,而R3期单株根重的增加反而会导致磷高效基因型单株粒重的下降。R3期株高、R3期和R8期地上部干重的增加都有助于磷低效基因型单株粒重的增加,而R3期、R5期和R8期的茎粗以及R5期叶片铁利用率的增加反而导致磷低效基因型单株粒重下降。而且,R8期单株地上部干重对磷高效和磷低效基因型的直接正向贡献均最大。(4)利用因子得分综合评价发现,P∶Fe≤100∶100时,磷高效和磷低效基因型在P∶Fe比为100∶100处理下的综合表现最好;当P∶Fe≥500∶100时,磷高效和磷低效基因型在P∶Fe比为1000∶100处理下的综合表现最好。综上,鼓粒初期可以作为筛选不同磷效率基因型的一个重要时期。在铁供应充足情况下,应考虑到土壤磷素累积和植酸对磷素效率影响问题,无论是磷高效还是磷低效基因型施P∶Fe比达到1∶1时整体表现最好。

缺铁条件下磷素水平对不同磷效率大豆农艺性状的影响

为给缺铁地区磷肥的合理施用提供理论依据,以磷高效和磷低效基因型大豆为材料,采用砂培方式研究不同磷/铁处理对不同磷效率大豆生物学性状的影响,分析农艺性状与大豆植株磷、铁性状的关系,以及磷、铁性状对单株粒重的影响,并利用因子得分综合评价磷高效和磷低效基因型对不同磷/铁处理的响应。结果表明:磷高效基因型大豆在R5期的株高、茎粗、单株叶面积、叶片干重、茎干重、荚干重、地上部干重和根系干重的最高值均出现在磷/铁为300∶30处理下。典型相关分析表明,磷高效基因型大豆R5期的地上部干重与R8期籽粒铁/磷浓度比呈正相关关系;磷低效基因型大豆R5期的地上部干重与R3期叶片磷浓度呈正相关关系。磷高效和磷低效基因型的单株粒重均与R8期籽粒铁浓度有关,但R8期籽粒铁浓度对两种基因型的作用相反,表明R8期籽粒铁浓度是影响低铁条件下不同品种单株粒重差异的重要指标。利用因子得分综合评价发现,磷/铁为1~10时,随着磷/铁比值的增大,磷高效基因型大豆的ACE值随之升高,而磷低效基因型大豆的ACE值随之下降。综上,缺铁胁迫下,磷高效基因型大豆在磷/铁为300∶30处理下的综合表现最好,磷低效基因型大豆在磷/铁为30∶30处理下的综合表现最好。

不同品种紫花苜蓿根系形态及生理特征对磷水平的响应

为明确不同品种紫花苜蓿(Medicago sativa)根系形态和生理特征对磷水平的响应,以营养液水培的试验方法,分析了0(P_(0))、50(P_(1))、100(P_(2))、500(P_(3))1000(P_(4))和1500μmol·L^(−1)(P_(5))磷水平下,6种紫花苜蓿根系形态及生理特征对磷水平的响应。结果发现,各品种总根长、根表面积均在P_(1)处理时达到最大,新牧一号、耐盐之星、肇东、巨能Ⅱ4个品种在P_(2)低磷水平时总根长、根表面积高于陇东、龙牧801。设定磷水平下,各品种根体积仅在P_(0)、P_(1)处理时存在差异性,陇东根体积在P_(1)、P_(2)、P_(3)、P_(5)处理下均小于其他品种。P_(1)处理时新牧一号、龙牧801根系磷吸收效率高于其他4个品种,P_(2)、P_(3)、P_(4)处理下肇东根系磷吸收效率显著(P<0.05)高于其他品种。根系酸性磷酸酶活性均在P_(1)时达到最大且同浓度磷水平时各品种间存在显著差异。低磷水平下,耐盐之星、巨能Ⅱ根系酸性磷酸酶活性显著高于其他4个品种,综合各耐低磷指标表明新牧一号、耐盐之星的耐低磷性高于其他品种是较好的磷高效品种,其次是肇东、巨能Ⅱ,而陇东、龙牧801则可归纳为磷低效品种。

Differentiation of Barley Genotypes with High Phosphorus Efficiency under Low Phosphorus Stress

[Objective] This study aimed to investigate differences in phosphorus effi-ciency between two-rowed barley and multiple-rowed barley and differences in phos-phorus efficiency among various agronomic traits, and to explore the relationship be-tween agronomic traits and row type with phosphorus efficiency. [Method] Under available phosphorus mass fractions of 1.32 and 36.6 mg/kg, 172 barley varieties, including 79 two-rowed foreign barley, 22 multiple-rowed foreign barley, 58 two-rowed Chinese barley and 13 multiple-rowed Chinese barley, were selected to com-pare differences in phosphorus efficiency-related agronomic traits. Plant height, spike length, number of unfil ed grains, number of unfil ed grains, main panicle weight, to-tal panicle weight, total stem weight, weight of aerial part and heading stage were surveyed for statistical analysis. [Result] The results showed that, various agronomic traits were larger under fertilization condition than under non-fertilization condition ex-cept number of unfil ed grains and heading stage. Plant high, spike length, weight of aerial part and heading stage varied greatly under non-fertilization condition; number of fil ed grains, number of unfil ed grains and total stem weight varied greatly under fertilization condition. In two-rowed barley, plant height and number of fil ed grains of Chinese varieties were higher than those of foreign varieties, while other agronomic traits such as spike length, number of unfil ed grains, main panicle weight, total panicle weight, total stem weight, weight of aerial part and heading stage of foreign varieties were higher than those of Chinese varieties. Spike length and weight of aerial part in multiple-rowed and two-rowed foreign barley were higher than those in Chinese barley. In multiple-rowed barley, plant height, number of unfil ed grains, total panicle weight and total stem weight of foreign varieties were higher under non-fer-tilization condition and lower under fertilization condition compared with those of Chi-nese varieties; number of fil ed grains, main panicle weight and heading stage of foreign varieties were lower under non-fertilization condition and higher under fertil-ization condition compared with those of Chinese varieties. [Conclusion] Heading stage, number of fil ed grains, number of unfil ed grains and total stem weight are more sensitive to phosphorus efficiency. Multiple-rowed barley is more sensitive to phosphorus efficiency than two-rowed barley.

Analysis of Phosphorus Nutrition Efficiency of Soybean Genotypes with Different Phosphorus Efficiency at Blooming Stage under Low Phosphorus Stress

[Objective] This study aimed to investigate the phosphorus nutrition effi- ciency of different soybean genotypes at blooming stage under low phosphorus stress. [Method] By using four ＂low phosphorus efficiency＂ soybean genotypes （D03, D05, D17 and D18） and four ＂high phosphorus efficiency＂ soybean genotypes （D31, D34, D37 and D38） as experimental materials, soil culture experiment was conduct- ed with two treatments of high phosphorus （＋P） and low phosphorus （-P）, to analyze the relationship between phosphorus content, phosphorus uptake, phosphorus use efficiency and phosphorus efficiency of soybean genotypes with different phos- phorus efficiency. [Result] Under low phosphorus conditions, four soybean genotypes with high phosphorus efficiency showed significant advantage in phosphorus uptake at seedling stage, to be specific, D34 showed relatively high phosphorus absorption capacity but no advantage in adaptability of phosphorus use efficiency, while only D37 showed relatively high phosphorus absorption capacity and phosphorus use ca- pacity. Correlation analysis and path analysis showed that the level of phosphorus efficiency of soybean at blooming stage under （-P） and （＋P） treatments was mainly determined by phosphorus absorption capacity, and that under （-P） treatment was significantly greater than （＋P） treatment. Phosphorus uptake and phosphorus use ef- ficiency under （-P） and （＋P） treatments both showed great direct effects on phos- phorus efficiency, and phosphorus uptake made greater contribution; however, the indirect effects were relatively low, Under low phosphorus stress, the mechanisms for various soybean genotypes with high phosphorus efficiency to adapt to low phospho- rus stress were different, and phosphorus absorption efficiency （phosphorus uptake） was the main variation source of the phosphorus efficiency of various soybean genotypes at blooming stage. [Conclusion] This study revealed the contribution made by phosphorus absorption efficiency and phosphorus use efficiency to phosphorus efficiency of soybean.

Effect of Temperature on Segregation Coefficients of Impurities in Phosphorus

The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatures of melting zone are obtained for zone pass n = 1 at travel velocity of molten zone v = 5x 10^-3 m. h^-1 and initial impu- rity concentration C0〈10 μg.g-1, lnkeff is a linear function of 1/T. The keff values of A1, Ca, Cr, Fe, Cd and Sb in- crease with temperatures while that of Mg is almost constant. The purification is acceptable at lower temperature of melting zone such as 323 K. The variations of enthalpy and entropy between impurities and phosphorus in the liq- uid and solid ohases are also 19resented.

Arbuscular mycorrhizae status of host plant affects offspring’s phenotype and transcriptome expression in a low-phosphorus environment

Although the effects of arbuscular mycorrhizal fungi(AMF)on host plants have been well documented,whether the effects of AMF on parental generations affect offspring performance is not fully clear.We conducted a common garden experiment to determine whether AMF status of host plants(Medicago truncatula)affects phenotype and transcriptome expression of their offspring.Seeds from four type parental treatments(low-phosphorus(P)soil without AMF,low-P soil with AMF,high-P soil without AMF and high-P soil with AMF)were grown under low-P(LPS)and normal-P soil(OHS)conditions.The fowering pattern of LP offspring was similar to their parents,such that plants with AMF fowered earlier than those without AMF under OHS condition but were opposite under LPS condition.The transcriptome differential analysis showed that some differential transcripts(45 for parental plants growing under low-P condition and 3 for parental plants growing under high-P condition)expression patterns between offspring were comparable,and that only affected by parental AMF status regardless of the P environment that offspring was grown.Others(146 for parental plants growing under low-P condition and 2 for parental plants growing under high-P condition),however,were affected both by the parental AMF status and the offspring P environment.In addition,the number of differential transcripts between offspring whose parental plants grew under high-P condition was far less than under low-P condition.These results indicate that AMF may not only affect the current generation of host plants but also affect the offspring especially when their parents have experienced a stressful environment.